In a typical coil processing operation coils of material such as sheet metal are placed upon an unwind stand, trained past a slitter and the slit coils then rewound on a rewind mandrel. Thereafter the rewind mandrel is collapsed and the slit, rewound coils are pushed off the rewind mandrel onto the horn of a turnstile, the turnstile horn having first been rotated into alignment with the rewind mandrel. The turnstile, now carrying the slit, rewound coils, is then rotated until its horn is aligned with the horn of a vertically oriented downlayer, and the coils pushed from the horn of the turnstile onto the horn of the downlayer. The downlayer is then pivoted to a horizontal position, its horn retracted, and the coils moved off the downlayer onto a conveyor.
Routine handling in the manner described above often results in damage to the coils in several different ways. For example, the tails or leading ends of the slit coil are held in a gripper slot in the rewind mandrel. It is quite common for these tails to become stuck in the gripper slot even after it has been opened, so that when an attempt is made to push the coils off the mandrel the coils tend to telescope and are damaged.
Furthermore, the mere act of sliding the coils from the madrel to the turnstile horn and from the turnstile horn to the downlayer horn will also often result in damage to the inside diameters of the coils.
Additionally, the edges of each wrap on each coil are quite often not aligned. Although adjacent coils are separated from each other on the rewind mandrel, it will be obvious that when an attempt is made to push the coils from one supporting member to another there is edge to edge contact between coils and the projecting edges may become bent over and damaged, thereby decreasing the efficiency of subsequent manufacturing operations using the damaged sheets, such as punch press operations.
It has also been found that, aside from outwardly projecting edges being bent in this manner it is quite common for such edges of adjacent coils to become interleaved. As a result, in later handling operations the coils must be pried apart from each other, markedly decreasing the speed and efficiency of the operation.